Natural wood shakes are a common siding and roofing product in the building market. This structural wood cladding is made from thin, narrow strips of wood, typically 0.125″-0.5″ (0.32 cm to 1.27 cm) thick at the thickest point, 4″ to 8″ (10.2 cm to 20.3 cm) wide and 12″ to 48″ (30.5 cm to 121.9 cm) long, which may or may not be tapered in thickness, and which form an overlapping structure on either a roof or wall in order to prevent moisture infiltration into the structure. Many consumers find wood shakes to be highly desirable from an aesthetic standpoint, but often select alternative sheathing products (e.g., asphalt shingles, steel roofing and siding, vinyl lap siding, or molded plastic or press-formed cementitious sheathing products) due to their lower initial cost and perceived longevity when compared to wood shakes. In addition to their relative high cost, wood shakes are prone to splitting, mildewing and rotting over time as a result of being exposed to prolonged moisture (rain, snow, high humidity) and excessive or insufficient sun conditions. Cedar is commonly used for wood shakes because of its higher resistance to rotting, but all cellulosic-containing materials (wood) will eventually deteriorate in high moisture environments. Cedar is also a premium, expensive building material as a result of limited sources of supply.
A further inherent challenge with natural wood shakes is their tendency to break or separate along the grain when nails are driven through the shakes during installation or when impacted during installation or during their service life (foot traffic, falling tree branches, hail, ice, etc.) They tend to be particularly fragile in the lengthwise direction due to the natural grain of the wood and the relatively low crack propagation resistance of the material. As a result, wood shakes cannot be significantly bent, impacted or nailed close to an end grain edge without expected crack propagation and possible separation of the material over some or all of its length. Pre-drilling nail holes can help minimize separation from nailing, but further adds to the cost as an extra step in the installation process. Thus it would be desirable to have a synthetic product that mimics the desirable aesthetics of wood shakes, but avoids or minimizes the issues with wood just described.
Known commercial synthetic products made to mimic wood shakes are made from injection molded plastic or cementitious materials and have had reasonable market success, but are also costly and still lack the authenticity of real wood shakes because they cannot match the true texture and rustic split-wood appearance that consumers associate with real split-wood shakes. Such molded and pressed products are substantially free of surface imperfections like fibrils or “tear-outs”, and as a result such molded and pressed products also lack the true random split grain texture that is inherent to real wood shingles which arises during a splitting operation from the nature of their wood grain which is not straight and typically comprises rings of varying density depending on growing season.